Ethnicity association of Helicobacter pylori virulence genotype and metronidazole susceptibility

Alfizah Hanafiah, Awang Hamat Rukman, Ahmad Norazah, Razlan Hamizah, Mohamed Ramelah

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

AIM: To characterise the cag pathogenicity island in Helicobacter pylori (H. pylori) isolates by analysing the strains' vacA alleles and metronidazole susceptibilities in light of patient ethnicity and clinical outcome. METHODS: Ninety-five H. pylori clinical isolates obtained from patients with dyspepsia living in Malaysia were analysed in this study. Six genes in the cag PAI region (cagE, cagM, cagT, cag13, cag10 and cag67) and vacA alleles of the H. pylori isolates were identified by polymerase chain reaction. The isolates' metronidazole susceptibility was also determined using the E -test method, and the resistant gene was characterised by sequencing. RESULTS: More than 90% of the tested isolates had at least one gene in the cag PAI region, and cag67 was predominantly detected in the strains isolated from the Chinese patients, compared with the Malay and Indian patients (P < 0.0001). The majority of the isolates (88%) exhibited partial deletion (rearrangement) in the cag PAI region, with nineteen different patterns observed. Strains with intact or deleted cag PAI regions were detected in 3.2% and 8.4% of isolates, respectively. The prevalence of vacA s1m1 was significantly higher in the Malay and Indian isolates, whereas the isolates from the Chinese patients were predominantly genotyped as vacA s1m2 (P = 0.018). Additionally, the isolates from the Chinese patients were more sensitive to metronidazole than the isolates from the Malay and Indian patients (P = 0.047). Although we attempted to relate the cag PAI genotypes, vacA alleles and metronidazole susceptibilities to disease outcome, no association was observed. The vacA alleles were distributed evenly among the strains with intact, partially deleted or deleted cag PAI regions. Interestingly, the strains exhibiting an intact cag PAI region were sensitive to metronidazole, whereas the strains with a deleted cag PAI were more resistant. CONCLUSION: Successful colonisation by different H. pylori genotypes is dependent on the host's genetic makeup and may play an important role in the clinical outcome.

Original languageEnglish
Pages (from-to)1283-1291
Number of pages9
JournalWorld Journal of Gastroenterology
Volume19
Issue number8
DOIs
Publication statusPublished - 2013

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Metronidazole
Helicobacter pylori
Virulence
Genotype
Alleles
Genes
Genomic Islands
Dyspepsia
Malaysia
Disease Susceptibility
Polymerase Chain Reaction

Keywords

  • Cag pathogenicity island
  • Helicobacter pylori
  • Metronidazole susceptibility
  • VacA alleles

ASJC Scopus subject areas

  • Gastroenterology

Cite this

Ethnicity association of Helicobacter pylori virulence genotype and metronidazole susceptibility. / Hanafiah, Alfizah; Rukman, Awang Hamat; Norazah, Ahmad; Hamizah, Razlan; Ramelah, Mohamed.

In: World Journal of Gastroenterology, Vol. 19, No. 8, 2013, p. 1283-1291.

Research output: Contribution to journalArticle

Hanafiah, Alfizah ; Rukman, Awang Hamat ; Norazah, Ahmad ; Hamizah, Razlan ; Ramelah, Mohamed. / Ethnicity association of Helicobacter pylori virulence genotype and metronidazole susceptibility. In: World Journal of Gastroenterology. 2013 ; Vol. 19, No. 8. pp. 1283-1291.
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AU - Hanafiah, Alfizah

AU - Rukman, Awang Hamat

AU - Norazah, Ahmad

AU - Hamizah, Razlan

AU - Ramelah, Mohamed

PY - 2013

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N2 - AIM: To characterise the cag pathogenicity island in Helicobacter pylori (H. pylori) isolates by analysing the strains' vacA alleles and metronidazole susceptibilities in light of patient ethnicity and clinical outcome. METHODS: Ninety-five H. pylori clinical isolates obtained from patients with dyspepsia living in Malaysia were analysed in this study. Six genes in the cag PAI region (cagE, cagM, cagT, cag13, cag10 and cag67) and vacA alleles of the H. pylori isolates were identified by polymerase chain reaction. The isolates' metronidazole susceptibility was also determined using the E -test method, and the resistant gene was characterised by sequencing. RESULTS: More than 90% of the tested isolates had at least one gene in the cag PAI region, and cag67 was predominantly detected in the strains isolated from the Chinese patients, compared with the Malay and Indian patients (P < 0.0001). The majority of the isolates (88%) exhibited partial deletion (rearrangement) in the cag PAI region, with nineteen different patterns observed. Strains with intact or deleted cag PAI regions were detected in 3.2% and 8.4% of isolates, respectively. The prevalence of vacA s1m1 was significantly higher in the Malay and Indian isolates, whereas the isolates from the Chinese patients were predominantly genotyped as vacA s1m2 (P = 0.018). Additionally, the isolates from the Chinese patients were more sensitive to metronidazole than the isolates from the Malay and Indian patients (P = 0.047). Although we attempted to relate the cag PAI genotypes, vacA alleles and metronidazole susceptibilities to disease outcome, no association was observed. The vacA alleles were distributed evenly among the strains with intact, partially deleted or deleted cag PAI regions. Interestingly, the strains exhibiting an intact cag PAI region were sensitive to metronidazole, whereas the strains with a deleted cag PAI were more resistant. CONCLUSION: Successful colonisation by different H. pylori genotypes is dependent on the host's genetic makeup and may play an important role in the clinical outcome.

AB - AIM: To characterise the cag pathogenicity island in Helicobacter pylori (H. pylori) isolates by analysing the strains' vacA alleles and metronidazole susceptibilities in light of patient ethnicity and clinical outcome. METHODS: Ninety-five H. pylori clinical isolates obtained from patients with dyspepsia living in Malaysia were analysed in this study. Six genes in the cag PAI region (cagE, cagM, cagT, cag13, cag10 and cag67) and vacA alleles of the H. pylori isolates were identified by polymerase chain reaction. The isolates' metronidazole susceptibility was also determined using the E -test method, and the resistant gene was characterised by sequencing. RESULTS: More than 90% of the tested isolates had at least one gene in the cag PAI region, and cag67 was predominantly detected in the strains isolated from the Chinese patients, compared with the Malay and Indian patients (P < 0.0001). The majority of the isolates (88%) exhibited partial deletion (rearrangement) in the cag PAI region, with nineteen different patterns observed. Strains with intact or deleted cag PAI regions were detected in 3.2% and 8.4% of isolates, respectively. The prevalence of vacA s1m1 was significantly higher in the Malay and Indian isolates, whereas the isolates from the Chinese patients were predominantly genotyped as vacA s1m2 (P = 0.018). Additionally, the isolates from the Chinese patients were more sensitive to metronidazole than the isolates from the Malay and Indian patients (P = 0.047). Although we attempted to relate the cag PAI genotypes, vacA alleles and metronidazole susceptibilities to disease outcome, no association was observed. The vacA alleles were distributed evenly among the strains with intact, partially deleted or deleted cag PAI regions. Interestingly, the strains exhibiting an intact cag PAI region were sensitive to metronidazole, whereas the strains with a deleted cag PAI were more resistant. CONCLUSION: Successful colonisation by different H. pylori genotypes is dependent on the host's genetic makeup and may play an important role in the clinical outcome.

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